Dimethylamine oxides as coating aids for photographic elements

ABSTRACT

Alkyldimethylamine oxides, e.g. lauryl-, cetyl-, myristyl-, and the like-, dimethylamine oxides are found to be particularly suitable for use as coating aids for gelatin-containing layers of photographic papers, films, plates, and the like. These coating aids are more especially suitable in multiple-layer coating techniques in making such elements.

United States Patent Inventor Wllllam J. Knox, Jr.

Rochester, N .Y.

App]. No. 719,672

Filed Apr. 8, 1968 Patented Sept. 21, 1971 Assignee Eastman Kodak Company Rochester, N.Y.

DIMETHYLAMINE OXIDES AS COATING AIDS FOR PHOTOGRAPHIC ELEMENTS 17 Claims, No Drawings US. Cl 96/1145, 106/125 Int. Cl G03c 1/38 Field of Search 96/1145 [56] References Cited UNITED STATES PATENTS 3,017,270 1/1962 Tregillus 96/663 3,113,026 12/1963 Sprung 96/1145 Primary Examiner-Norman G. Torchin Assistant Examiner-Judson R. Hightower Attorneys-W. H. J. Kline, Bernard D. Wiese and Gordon L.

Hart

' ABSTRACT: Alkyldimethylamine oxides, e.g. lauryl-, cetyl-,

DIMETHYLAMINE OXIDES AS COATING AIDS FOR PHOTOGRAPHIC ELEMENTS This invention relates to photography and particularly to improvements in making photographic recording elements which comprise one or more layers that contain a hydrophilic colloid such as gelatin or the like.

It is known that in coating layers comprising a hydrophilic colloid such as gelatin to make a photographic element, it is preferable to employ a wetting agent which is present in the aqueous coating solution during the coating process to improve the coating process and to improve the physical characteristics of the coated layer. The most widely used wetting agent for this purpose has been saponin, used either alone or in combination with another wetting agent. Other selected wetting agents have been proposed as coating aids for gelatin layers and the like, usually to obtain some particular desired property offered by the particular selected wetting agent.

An object of the present invention is to provide improved photographic elements comprising at least one hydrophilic colloid layer coated with an (aliphatic hydrocarbon) dimethylamine oxide wetting agent. Preferred embodiments of the invention provide coated photographic films, papers, plates and the like having relatively low surface coefficient of friction and having exceptional developer wettability. The coating aids of the invention are especially useful in modern high speed hopper-coating techniques and in such coating processes that involve coating of one layer on another wet layer (wet-on-wet coating).

The particular wetting agents, useful in accordance with the present invention as coating aids for hydrophilic colloid layers of photographic elements, are dimethylamine oxides having the formula wherein R is an aliphatic hydrocarbon group containing 7 to 2] carbon atoms and preferably a hydrocarbon such as alkyl and alkenyl groups derived from fatty acids.

Especially preferred dimethylamine oxides of this class are the series known by the trade name Ammonyx tertiary amine oxides available from Onyx Chemical Company, Jersey City 2, NJ., U.S.A. This series includes lauryldimethylamine oxide (Ammonyx LO), cetyldimethylamine oxide (Ammonyx CO), myristyl-dimethylamine oxide (Ammonyx MO), myrystylcetyldimethylamine oxide (Ammonyx MCO) and others having longer chain aliphatic hydrocarbons derived from fatty acids such as stearic acids and tallow fatty acid (Ammonyx SO, TO).

Wetting agents of the class described are found especially useful as coating aids for machine coating of photographic silver halide emulsion layers with other layers comprising a hydrophilic colloid which preferably is gelatin but may be another hydrophilic colloid such as poly(vinyl alcohol), acrylate, methacrylate, and acrylamide polymers including copolymers and other synthetic polymers either along or in mixture with gelatin or other colloids.

The class of wetting agents useful in accordance with this invention also is helpful when incorporated in layers other than the emulsion layer, such as gelatin subs or gelatin overcoats, multiple emulsion layers such as those in color films and papers, auxiliary layers in photographic recording elements, such as l'ilter layers, antistatic layers, antihalation layers, pig ment or baryta layers and the like. The wetting agent can be incorporated in one or all or in selected ones of multiple hydrophilic colloid layers of a photographic recording element. The coating aids of this invention are found to be especially suitable for use in processes that involve the simultaneous application of two or more colloid layers to film base or paper.

The (aliphatic hydrocarbon)-dimethylamine oxides are found to have excellent metal-wetting properties and so are especially useful for eliminating pencil line streaks that often occur in coatings made by hopper coating machines. Such streaks are most often caused by contamination of the hopper surfaces by various hydrophobic inhomogeneities. The metalwetting action of the coating aid tends to inhibit this contamination.

This class of wetting agents when incorporated in hydrophilic colloid coating solutions tends to produce a very smooth coated surface having an unusually low coefficient of friction. Accordingly, these wetting agents will be especially useful for making silver halide recording elements when an extremely smooth or slick surface is desired.

The wetting agents of the class described produce coated colloid layers having excellent developer wettability so they are particularly useful for making photographic elements intended for wet processing, such as processing in aqueous developer and fixer solutions.

In addition to the particular properties mentioned above, the wetting agents provide other coating improvements found advantageous for making photographic elements. They provide wetting properties generally favorable for elimination of surface repellencies that might be caused by wetting imperfections between the coated colloid solution and the receiving support. These (aliphatic hydrocarbon-dimethylamine oxide wetting agents are generally compatible with the gelatin or other hydrophilic colloids, and with the photosensitive silver salts, as well as with most photographic processing formulas and most color forming constituents in color films and papers, etc. They will be generally compatible with other wetting agents and can be used in combination with various other wetting agents such as anionic, cationic, nonionic and amphoteric wetting agents that can be also present in the coated hydrophilic colloid layers.

As is generally true of wetting agents useful as coating aids, the present ones will be effective when incorporated in very minor proportions in the coating solutions. We obtain useful improvements using from about 0.07 up to about 1 gram in each pound of the coating solution before coating. One preferred range is about 0.13 to about 0.5 gram per pound of the solution. We prefer to employ the least amount necessary to obtain the desired improvement, as excessive amounts may unnecessarily cause some impairment of photographic properties.

The invention can be more readily understood by reference to the following example which sets out in detail a most preferred mode of carrying out the invention.

EXAMPLE 1 Two coating solutions are prepared, one a 13 percent gelatin aqueous solution, called an overcoat solution and the other a conventional silver bromoiodide, aqueous gelatin photographic emulsion, each of a kind used for making the emulsion layer and the protective overcoat of a conventional projection speed photographic black-and-white printing paper. Both the emulsion and the overcoat are varied from their standard formulas only by omission of the wetting agent, usually incorporated as a coating aid. The emulsion is divided into aliquot portions and to respective portions are added measures of Ammonyx CO, Ammonyx LO, Ammonyx MO, and Ammonyx MCO, each in varying proportions as indicated in Table l. A portion of the emulsion without coating aid is kept for control coatings.

The gelatin overcoat solution is divided into respective portions and to each is added one of the same Ammonyx wetting agents at concentration of 0.5 gram per pound of the solution ready for coating. A portion is saved without added wetting agent for the control coating.

The emulsion and overcoat solutions are coated by a sue tion slide hopper multilayer coating machine which lays down simultaneously the emulsion and overcoat layers. The support used is a conventional photographic printing paper support and the coating procedures are the same as would be used for coating of the same emulsion and overcoat in making the conventional printing paper for which they are designed. These coatings are laid down at 60 feet per minute, 35 C. After coating, the coating is chilled and then dried conventionally by circulating air.

Additional coatings also are made in the same way except with no coating aid in the emulsion and with a different one of the respective coating aids in the overcoat of each respective strip. Control strips are made the same except with no coating ad in either the emulsion or the overcoat. All of the coatings are cut into sheets for physical and sensitometric testing. A sheet from each strip is immediately examined visually for pencil line streaks and for visible surface repellencies. Fresh and incubated samples from each coated strip are tested sensitometrically, making measurements of gamma, D photographic speed and fog. Compared with a control sample, the samples containing the (aliphatic )-dimethylamine oxide coating aids show no significant difference in photographic properties. Other samples from the same coated strips are tested physically for developer spread and coefficient of friction. The test samples show significantly better developer spread, which is measured by an air bells" test and is an indication of wettability of the surface by a photographic developer. The test samples show significantly lower coefficient of friction than the control samples.

Selected results of the tests are tabulated in Table I.

TABLE I Instead of using gelatin as in the foregoing example, one may practice the invention using other hydrophilic colloids in the coating compositions used in photographic films, plates, papers and the like. Satisfactory colloids which can be used for this purpose include any of the hydrophilic colloids generally employed in the photographic field, including, for example, gelatin, colloidal albumin, polysaccharides, cellulose derivatives, synthetic resins such as polyvinyl compounds, including polyvinyl alcohol derivatives, acrylamide polymers and the like. In addition to the hydrophilic colloids, the vehicle or binding agent can contain hydrophobic colloids such as dispersed polymerized vinyl compounds, particularly those which increase the dimensional stability of photographic materials. Suitable compounds of this type include water-insoluble polymers of alkyl acrylates or methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates and the like. Such layers can be functional in the photographic element as sublayers, protective overcoats, antihalation or antistatic backings, filter layers, dye bearing layers, various emulsion layers, diffusion transfer receiving layers, reflective layers, or for other functions in a photographic element. The coating aids can be used in silver halide emulsion layers of various compositions as, for example, silver chloride, bromide, bromoiodide, chlorobromide, etc., emulsions. Including high speed silver halide emulsions such as emulsions sensitized with sulfur, selenium, tellurium and/or noble metal compounds such as gold sensitizers. They are especially useful for multiple layer coating of emulsion and protective layers simultaneously Surfactant concentration,

.llb.

Dev. Coeflicient of {tie Wetting agent Emulsion Overcoat spread tion Sample No.:

1 Ammonyx 00.... 0.00 0.5 16.6 0.13 do 0.13 0. 5 16. 6 0. 11 0. 25 0. 5 16. 6 0. 11 0. 0. 5 16. 6 0. 12 0. 00 0. 5 16. 6 0. 14 0. 13 0. 5 16. 6 0. 14 0. 25 0. 5 16. 6 0. 12 0. 50 0. 5 16. 6 0. 15 0. 00 0. 5 16. 6 0. 14 0. 13 0. 5 16. 6 O. 14 0. 25 0. 5 16. 6 0. 12 0. 50 0. 5 16. 6 0. 15 0. 00 0. 5 16. 6 0. 15 0. 13 0t 5 16. 6 0. 15 0. 25 O. 5 16. 6 0. 18 0. 50 0. 5 16. 6 0. 16 None None 4. 52 0. 44

Note-No repellencies were observed on any of the test and control samples.

Results of these tests indicate the coating aids of the invention will be especially useful in making multiple coatings of hydrophilic colloid layers in photographic elements when a very smooth surface is wanted, when superior developer wettability is wanted, or for similar coating applications in cases where pencil line streaks or surface repellencies present a particular problem.

The foregoing specific example illustrates in detail only a preferred mode of carrying out the invention. Generally, in accordance with the invention, the class of (aliphatic hydrocarbon)-dimethylamine oxides will be useful coating aids for improving a variety of different kinds of hydrophilic colloid layers coated on a variety of supports. The invention is especially suited to making multiple-layer coatings on supports such as on paper sheets, glass plates, synthetic resin films such as cellulose ester or poly(ethylene terephthalate) films, and the like. In some preferred embodiments the coating aids can be used to advantage when present only in an auxiliary layer coated in a multiple layer element having another layer that contains the photosensitive silver halide. This is illustrated in the above example by those coating runs in which only the gel overcoat contains the coating aid.

on paper support, and for coating of mordanted dye layers in color photographic elements. Elements comprising colloid layers containing the coating aids of this invention can be negative films, reversal films, medical X-ray films, black-andwhite or color films or printing papers, or any of the other types of recording elements that comprise hydrophilic colloid coatings. Emulsions layers coated with the coating aids of the invention can be emulsion sensitized by any of the known techniques using any of the various chemical and spectral sensitizers and other adjuvants employed in emulsion making. The coating aids can be used for coating on any suitable support. The coating aids can be used in one or several coated colloid layers of an element. Supports suitable for receiving the colloid layers include cellulose nitrate, cellulose acetate, poly(vinyl acetal polystyrene, poly(ethylene terephthalate) film, baryta coated papers, polyethylene or other polyolefin coated papers, and the like.

Colloid layers coated with coating aids of the present invention can also comprise any of the various suitable hardeners such as chrome alum, aldehydes such as formaldehyde or mucochloric acid, aziridine hardeners, derivatives of dioxane, oxypolysaccharides such as oxystarch or oxy plant gums, etc. Layers coated with the coating aids can contain or can be coated in elements containing other additives such as lubriamino-propionates, palmityl palmitate, or containing various plasticizers. Elements comprising coating aids of the invention can be processed in any of the various developing and finishing processes known for producing finished photographs. Layers coated with these coating aids can contain or be incorporated in elements containing incorporated developers such an polyhydroxybenzenes, aminophenols, 3-parazolidones, including dye-developers of the type described in Rogers U.S. Pat. No. 2,983,606 patented May 9, 1961.

The coating aids can be used in contact with other suitable wetting agents, which can be included in the same layer with the present coating aids, or in another layer of an element comprising several layers. Such other wetting agents can include nonionic, cationic, anionic, or other amphoteric types,. for example, polyoxyalkylene derivatives, amphoteric amino. acid dispersing agents such as sulfobetaines and the like. Suitable other wetting agents are described in U.S. Pat. Nos. 2,600,831 patented June 17, 1952; 2,271,622 and 2,271,623 patented Feb. 3, 1942; 2,275,727 patented Mar. 10, 1942: 2,787,604 patent el Apr. 2,1957; 2,816,920 patented D ec.

17, 195 7; 2,7 ,89l paten ted Mar. 27, 1956; and Bi'itisH Pat.

The coating aids of the invention can be used in colloid layers containing, or in colloid layers of elements comprising other layers containing, emulsion stabilizers or antifoggants, particularly noble metal compounds described in U.S. Pat. Nos. 2,566,245, 2,566,263, and 2,597,856; triazaindolines described in U.S. Pats. Nos. 2,444,605, 2,444,606, and 2,444,607, or containing speed-increasing materials, absorbing dyes and the like, or containing as sensitizers alkylene oxide polymers which can be employed alone or with other materials such as quaternary ammonium salts as disclosed in U.S. Pat. No. 2,886,437 or with mercury and nitrogen compounds as described in U.S. Pat. No. 2,751,299.

Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, variations and modifications can be effected within the spirit and scope of the invention as described hereinbefore and as defined in the appended claims.

1 claim:

1. In a photographic element comprising a photosensitive layer of silver halide'hydrophilic colloid emulsion and another discrete hydrophilic colloid layer, the improvement wherein at least said discrete hydrophilic colloid layer contains as a coating aid a minor amount from about 0.07 to 1 gram per pound of coating solution of an (aliphatic hydrocarbon)- dimethylamine oxide, said aliphatic hydrocarbon radical containing from 7 to 21 carbon atoms.

2. An improved method of making a photographic element which s mpr s s hatqssssitiyqlsysr 9 flxsahalisls-tzrsiraphilic colloid emulsion and a discrete hydrophilic colloid layer containing no silver halide, said improved method comprising the step of coating on a support with said emulsion layer a discrete hydrophilic colloid layer as an aqueous colloid solution which contains as a coating aid a minor amount from about 0.07 to 1 gram per pound of coating solution of an (aliphatic hydrocarbon)dimethylamine oxide, said aliphatic hydrocarbon radical containing 7 to 21 carbon atoms.

3. An improved method defined by claim 2 wherein said emulsion layer also contains a minor amount from about 0.07

to 1 gram per pound of coating solution of a coating aid of the same class defined.

4. An improved method defined by claim 2 wherein said discrete hydrophilic colloid layer is a protective gelatin layer coated over said emulsion layer.

5. An improved method defined by claim 2 wherein said dis crete hydrophilic colloid layer is coated immediately next to said emulsion layer while both said layers contain the water vehicle with which they are coated.

6. An improved method defined by claim 2 wherein said discrete hydrophilic colloid layer is coated immediately over said emulsion layer while both said layers contain the water vehicle with which they are coated.

7. An improved method defined by claim 2 wherein the hydrophilic colloid of both said layers is gelatin.

8. An improved method defined by claim 2 wherein the defined coating aid is present in said discrete hydrophilic col loid layer in an amount from 0.07 to 0.5 gram per pound of wet cdating solution.

9. A photographic element comprising at least two discrete coated layers on a support, at least one such layer comprising silver halide, and at least one of such layers comprising as a coating aid a minor amount from about 0.07 to 1 gram per pound of coating solution of an (aliphatic hydrocarbon dimethylamine oxide, said aliphatic hydrocarbon radical containing from 7 to 21 carbon atoms. a

10. The photographic element of claim 1 wherein the coating aid is lauryldimethylamine oxide.

The photographic element of claim 1 wherein the coating aid is cetyldimethylamine oxide.

12. The photographic element of claim 1 wherein the coating aid is myristyldimethylamine oxide.

13. The photographic element of claim 1 wherein the coatingaid is myristyl-cetyldimethylamine oxide.

4. The improved method of claim 2 wherein the coating aid is lauryldimethylamine oxide.

15. The improved method of claim 2 wherein the coating aid is cetyldimethylamine oxide.

16. The improved method of claim 2 wherein the coating aid is myristyldimethylamine oxide.

17. The improved method of claim 2 wherein the coating aid is myristyl-cetyldimethylamine oxi de. 

2. An improved method of making a photographic element which comprises a photosensitive layer of silver halide-hydrophilic colloid emulsion and a discrete hydrophilic colloid layer containing no silver halide, said improved method comprising the step of coating on a support with said emulsion layer a discrete hydrophilic colloid layer as an aqueous colloid solution which contains as a coating aid a minor amount from about 0.07 to 1 gram per pound of coating solution of an (aliphatic hydrocarbon)-dimethylamine oxide, said aliphatic hydrocarbon radical containing 7 to 21 carbon atoms.
 3. An improved method defined by claim 2 wherein said emulsion layer also contains a minor amount from about 0.07 to 1 gram per pound of coating solution of a coating aid of the same class defined.
 4. An improved method defined by claim 2 wherein said discrete hydrophilic colloid layer is a protective gelatin layer coated over said emulsion layer.
 5. An improved method defined by claim 2 wherein said discrete hydrophilic colloid layer is coated immediately next to said emulsion layer while both said layers contain the water vehicle with which they are coated.
 6. An improved method defined by claim 2 wherein said discrete hydrophilic colloid layer is coated immediately over said emulsion layer while both said layers contain the water vehicle with which they are coated.
 7. An improved method defined by claim 2 wherein the hydrophilic colloid of both said layers is gelatin.
 8. An improved method defined by claim 2 wherein the defined coating aid is present in said discrete hydrophilic colloid layer in an amount from 0.07 to 0.5 gram per pound of wet coating solution.
 9. A photographic element comprising at least two discrete coated layers on a support, at least one such layer comprising silver halide, and at least one of such layers comprising as a coating aid a minor amount from about 0.07 to 1 gram per pound of coating solution of an (aliphatic hydrocarbon)-dimethylamine oxide, said aliphatic hydrocarbon radical containing from 7 to 21 carbon atoms.
 10. The photographic element of claim 1 wherein the coating aid is lauryldimethylamine oxide. ,11. The photographic element of claim 1 wherein the coating aid is cetyldimethylamine oxidE.
 12. The photographic element of claim 1 wherein the coating aid is myristyldimethylamine oxide.
 13. The photographic element of claim 1 wherein the coating aid is myristyl-cetyldimethylamine oxide.
 14. The improved method of claim 2 wherein the coating aid is lauryldimethylamine oxide.
 15. The improved method of claim 2 wherein the coating aid is cetyldimethylamine oxide.
 16. The improved method of claim 2 wherein the coating aid is myristyldimethylamine oxide.
 17. The improved method of claim 2 wherein the coating aid is myristyl-cetyldimethylamine oxide. 